1. Field of the Invention
This invention relates to an antenna arrangement for radar, or for direction finding purposes, respectively, with sum and difference patterns for monopulse operation, and more particularly to such an arrangement comprising a reflector and at least two linear polarized exciters which are located approximately in the center between which perpendicular to their polarization direction a metallic conductive plane dividing wall is arranged reaching up to the reflector and extending perpendicularly thereto.
2. Description of the Prior Art
An antenna arrangement consisting of two reflector halves each having an exciter is known from the British Pat. No. 1,105,503. The two reflector halves are separated by an interim piece of approximately 3/8.lambda. so that two clearly separated focal points will result whereat the exciters are located. A dividing wall is arranged between the exciters for decoupling of the two antenna halves. Therefore, two symmetrical and evenly constructed antenna halves are created, whereby one is merely used for transmitting and the other one exclusively for receiving. An interacting of both antenna halves, such as for example takes place in monopulse direction finding with sum and difference patterns is thus excluded.
The German Offenlegungsschrift No. 1,953,743 discloses an antenna arrangement for radar or direction finding purposes, respectively, for monopulse operation comprising a reflector and linearly polarized exciters which are arranged symmetrically with respect to the focal point, between which a continuous plane dividing wall extending to the reflector is interposed perpendicularly to the direction of polarization. Thus, two completely separated and decoupled antenna halves are created of which each, for example, is excited by a horn radiator with mirror image. In sum, as well as in difference operation, therefore the primary diagram and thus the illumination of both reflector halves remains unchanged. The radiation characteristics obtained are very favorable. Only in case of radar-equipments, the angular range, which can be jammed by electronic countermeasures, is in the difference channel,relatively large.